The Long Run might well be the most mythical workout in the world of running. Whether your goal is a 5k or an ultra-marathon, the long run is a steady part of your running week. That’s the beauty and simplicity of this crucial workout.

One long run per week, usually done at a fairly easy pace, helps improve aerobic capacity and efficiency. The idea isn’t to be completely out of breath and dead after this run, it’s to practice being on your feet for a growing length of time, and to spend time at a pace you can hold comfortably as you increase distance or time. Done week after week, it’s a great way to track your progress and slowly work your way to your goal distance.

If you’re training for a 5k, this could be anywhere from 30 to 40 minutes, and if you’re working your way to a marathon, it might start at 60 minutes and end up at 2 – 3 hours at the end of your training plan.

There are a few ways to structure your long run:

For time: If you don’t like to track your pace or just want a simple way to track your long run, go out for a certain length of time. Running for time means you don’t have to worry about how fast you’re going, which can be a relief if it’s been a long week and you’re feeling extra tired or sore from another workout. Turn off your brain and plan a long loop, or run one direction for half the length of your run before turning around and working your way back.

For distance: If you’re motivated by seeing miles add up, or want to hit specific mile splits for your long run, running for distance can be really useful. On a 15-mile run, for example, you could run 5 miles easy, 5 miles at goal pace plus + 30 seconds per mile, and the last 5 miles as close to goal race pace as you can get. Of course you can do a similar long run in time chunks, but using miles as the discrete units can be a really easy way to break up the workout and see how well you hit your paces.